linux dig command
The dig command is a very useful tool to perform/test dns resolution on the client side. It performs similar functions to the more ancient nslookup command.
to get the ip(s) in the A record of a fully qualified domain name with the details of the answer (TTL, DNS server ip etc)
if you are not interested in the details, you can use "+short" to get only the ip(s) in the A record
to bypass your local resolver, and see the recursive query starting at the root dns servers, use "+trace" to see the whole chain of resolution
to use a specific resolver
to get the ipv6 address of a fully qualified domain name
to get the authoritative name servers for a given domain
to get the mail exchangers(MX) servers for a given domain
to get the reverse dns record for a given ip
to get a txt record for a given domain